Number: 139

Unofficial Title: Topology

Title: Mmmm... Doughnuts

Precedes: 138

Text: The board is topologically a torus containing an equal number of rows and columns, such that the "leftmost" column of the board is immediately to the right of the "rightmost" column, and the "topmost" row is immediately beneath the "bottommost" row. Columns are lettered in sequence rightwards on the board, beginning with A, and rows are numbered in sequence upwards on the board, beginning with 1. The periphery, or side, of the board is defined as Column A and the column immediately to its left, and Row 1 and the row immediately beneath it. The centre cell is defined as that cell furthest from the periphery.

Author: Initial Ruleset